The invention relates to a device for alternately supplying fluids to either line of a tandem line centralized distribution system.
Particularly but not exclusively referring to control tandem line lubricating systems, it it known that such systems comprise a lubricant (fluid) reservoir associated with a piston pump operated through a reduction gear by an electric motor. A lubricant supplied by the pump reaches a slide valve, also operated by a motor or other device, such as electromagnetic device, supplying either of the lines. The two lines supplied by the slide valve and along which the use locations, such as feeders, are distributed, terminate with electric contact members becoming effective when a desired pressure has been attained in the respective line. When one of the lines is at the maximum operating pressure, the electric motor driving the pump is stopped, whereas the motor or device controlling the slide valve is started. When the slide valve reaches the end of stroke position, the associated driving device is stopped by electric contact members also starting the pump motor and then the pump can supply fluid to the other line.
Conventional approaches have substantial disadvantages due to the provision of two electric motors or devices adding to the overall size of the equipment (pump plus reversing unit), and particular expedients would be required for providing the desired timing.